Texas DSHS warned that because the initial patient attended a movie theater in the area, others who attended the same theater should be on the lookout for symptoms.

Not getting vaccines has been a growing trend in the United States, and Texas is particularly vulnerable to outbreaks like this — it’s one of 19 states that gives parents the right to “opt out” of public school vaccination requirements. As the anti-vaccination movement has expanded through the years, public health experts have warned about the recurrence of outbreaks of diseases like measles.

According to the World Health Organization (WHO), measles is a highly contagious virus with a reproduction number of 12 to 18. For every person who contracts the virus, they can then transmit the virus to 12 to 18 unvaccinated people. The WHO says in order for herd immunity to stop the spread of measles, communities need to be vaccinated at a rate of 90 to 95 percent.

While many parents in these “opt out” states do have the right to make decisions on what they think is best for their kids medically, it’s vital to realize the decision to not vaccinate kids can have a disastrous effect on the communities around them — vulnerable people like the very young and very old, cancer patients, and anyone else with compromised immune systems.

Stories like this one out of Texas prove herd immunity matters. Vaccines matter. Keeping the public healthy benefits the greater good.